Does anyone have a simple method to take off the RF output from these rigs and safely input it to a scope to check the splatter? ?I have a 60 MHz scope but don't know how to use it correctly. ?That might help some of us reduce the spurs until we can learn how to do other mods. There are a lot of scopes out there to beg or borrow, mostly just sitting there in a shack or at a radio club. ?There are two sitting at our club but few know what to do with them. ?Sad story.
Dave K8WPE
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On Sep 4, 2018, at 3:13 PM, Jerry Gaffke via Groups.Io <
jgaffke@...> wrote:
We should have some way to indicate when too much mike gain is applied.
A diode, cap and resistor watching either audio or IF or RF peak signal levels, sending that to
a Nano analog pin should be sufficient.? Firmware shows a warning in the LCD if level exceeded.
I'd go with that, and a pot for mike gain.
If you insist on ALC:?
/g/BITX20/message/56796?
Jerry
On Tue, Sep 4, 2018 at 10:45 AM, Warren Allgyer wrote:
Your analysis is true so long as the tones, or the voice if that is your mode, do not overmodulate either the audio or the RF chain. In the case of the uBitx running 10 watts of SSB, whether it is voice or tones, one or both of those stages are significantly over-modulated to the extent they put splatter into the adjacent channels on either side. This splatter will not affect anyone listening to the SSB channel but will dramatically affect those 3 KHz up and down from that channel. The effect is far worse than on a full-featured SSB transceiver in that there is no ALC or compression to control the level.
My unit, a sample of one, over-modulates at any power level greater than 1.5 watts. Most do not care as you can hear most days on 7200 KHz..... but for those who do, you are on notice.
